An integrated circuit, e.g., a computer chip, may often include one or more Analog-to-Digital Converters (ADCs) to measure DC and/or low frequency voltages, such as analog bias voltages, on the integrated circuit.
Traditional ADCs, such as single bit sigma-delta converters, may consume significant amount of chip area and power. Such ADCs may also require good quality passive components, including resistors, capacitors, etc., which may impose additional requirements to the fabrication process.
Some traditional ADCs may use a comparator/sweep technique to measure the external voltages, in which a comparator may be used to successively compare an external voltage with the on-die voltage. However, such ADCs may be slow due to the amount of time it takes to sweep the external voltage, even if a binary search algorithm is used. In addition, comparator off-set may often contribute to the inaccuracies.